1. Field of the Invention
This invention relates to liquid propellant guns utilizing a differential piston to provide continued or regenerative injection of propellant into the combustion chamber.
2. Prior Art
Liquid propellant guns utilizing differential pistons to pump propellant into the combustion chamber during combustion are now well known. Early work is described in a Final Report of Nov. 19, 1953-Jan. 31, 1956 under contract DA-36-034-ORD-1504RD, Project TS1-47-8 by V. M. Barnes, Jr. et al which apparently in part corresponds to Jukes et al, U.S. Pat. No. 3,138,990, filed Oct. 9, 1961; in a report No. 17-2 of June 15, 1954 under contract NOrd-10448 by C. R. Foster et al; and in a Final Report of Sept. 1, 1957 under contract NOrd 16217, Task 1, by L. C. Elmore et al. Other patents of interest are J. W. Treat, Jr., U.S. Pat. No. 2,922,341, filed Nov. 7, 1955; E. J. Wilson, Jr. et al, U.S. Pat. No. 2,981,153, filed Nov. 14, 1952; C. M. Hudson, U.S. Pat. No. 2,986,072, filed Nov. 19, 1952; E. J. Vass et al, U.S. Pat. No. 3,690,255, filed Oct. 1, 1970; and D. P. Tassie, U.S. Pat. No. 4,023,463, filed June 10, 1976. A round of ammunition having a differential piston which is coaxial with the firing bore is shown by E. Ashley in Ser. No. 469,507, filed May 13, 1974, now abandoned. Reference may also be made to an article "Direct Injection Liquid Propellant Gun Technology" by Penn, Campbell and Bulman, CPAI Publication 280, June 1977, pp 257-303, which shows a differential piston which is coaxial with a firing bore in a gun.